The present invention relates to a chair, having a seat and a mechanism for securing the seat with adjustable inclination to a seat support bar that is connected to a center column.
Such a chair may for instance be an office chair, conference chair, visitor's chair, or the like. The inclination of the seat and/or of the backrest may be adjustable.
German Patent Disclosure DE 44 03 123 A1 describes a synchronous adjustment, in which the ratio between the inclination of the seat and the inclination of the backrest is adjustable. The synchronous adjusting mechanism is formed here by a plurality of pivotably connected-together parts and by a force-storing element, in this case a gas spring. Because of the large number of component parts, the known synchronizing mechanisms are relatively complicated and expensive, however. Moreover, the service life of the known adjusting mechanisms is limited, because of the large number of moving parts that are hence subject to wear.
In German Utility Model DE 297 04 906 U1, a chair with a synchronous adjustment is presented, in which the seat surface is secured to the chair column by means of a first, elastically deformable spring element. The backrest is secured, via a backrest support bar, to a second elastically deformable spring element that is coupled to the first spring element. The first spring element, or the seat surface, is moreover connected elastically or pivotably to the second spring element or to the backrest support bar. As a result, the aforementioned disadvantages of earlier mechanisms for synchronous adjustment are partly avoided, and in particular a long service life and a minimum of noise upon actuation are achieved. However, in this version as well, many mechanical parts are provided, making for a corresponding amount of effort of assembly and risk of wear. Moreover, with it, arbitrary, continuously variable relative adjustment of the seat surface and backrest cannot be attained.